Shampoo composition

ABSTRACT

A SHAMPOO COMPOSITION SUITABLE FOR SIMULTANEOUSLY CLEANSING AND CONDITIONING HUMAN HAIR, COMPRISING IN COMBINATION A WATER-SOLUBLE NON-SOAP ORGANIC SYNTHETIC DETERGENT SALT HAVING A HYDROPHOBIC LONG CHAIN SUBSTITUENT CONTAINING AT LEAST 8 CARBON ATOMS IN ITS MOLECULAR STRUCTURE AND A NORMALLY LIQUID SATURATED BRANCHED-CHAIN HIGHER FATTY ACID MATERIAL CONTAINING ABOUT 12-24 CARBON ATOMS. PREFERRED COMPOSITIONS CONTAIN ABOUT 10-40% BY WEIGHT OF THE DETERGENT AND 0.5 TO 5.0% BY WEIGHT OF THE FATTY ACID MATERIAL IN AN AQUEOUS MEDIUM.

United States Patent 3,590,122 SHAMPOO COMPOSITION Karl HutchesonRoberts, Flemington, and Marion Anthony Gomolka, Colonia, N.J.,assignors to Colgate- Palmolive Company, New York, N.Y. N0 Drawing.Filed May 12, 1967, Ser. No. 637,898 Int. Cl. A61k 7/06 US. Cl. 424-70 1Claim ABSTRACT OF THE DISCLOSURE A shampoo composition suitable forsimultaneously cleansing and conditioning human hair, comprising incombination a water-soluble non-soap organic synthetic detergent salthaving a hydrophobic long chain substituent containing at least 8 carbonatoms in its molecular structure and a normally liquid saturatedbranched-chain higher fatty acid material containing about 1224 carbonatoms. Preferred compositions contain about 10-40% by weight of thedetergent and 0.5 to 5.0% by weight of the fatty acid material in anaqueous medium.

BACKGROUND OF INVENTION The invention relates to a substantially stableliquid shampoo composition comprising in combination a major proportionof a synthetic organic non-soap detergent salt having a hydrophobic longchain substituent containing at least 8 carbon atoms in its molecularstructure and a minor proportion of a normally liquid, saturated,branched-chain fatty acid material in an aqueous medium whichsimultaneously cleanses and conditions the hair.

Shampoo compositions may be described generally as preparationscomprising a surfactant or surface active material which When used underthe conditions specified will remove surface grease, dirt and skindebris from the hair and scalp without adversely affecting the hair,scalp or health of the user.

Originally, the shampoos were made of soap or mixtures of soaps, whereastoday synthetic detergents are the primary surfactants used in thecommercial products. Although soap shampoos comprising primarily eithersalts of C -C or salts of G -C fatty acids had the respectivedisadvantages of being irritating to the skin and of possessinginadequate solubility properties, shampoos, containing mixtures of saltsof C -C fatty acids, e.g., olive oil soaps, were found to haveoutstanding cleansing and conditioning properties in soft water.However, these same shampoos proved ineffective in medium and hard waterdue to the formation of insoluble calcium and magnesium soaps which weredeposited as sticky films on the hair.

To avoid the problem of insoluble soap precipitates associated with hardwater, non-soap synthetic detergents were used in place of soap as theprimary surfactant in shampoo compositions. While use of certainnon-soap synthetic detergents resulted in enhanced foaming and cleansingaction, the resultant shampoo compositions had little or no hairconditioning properties. Accordingly, it became necessary to add specialexpensive finishing agents such as unsaponified oils, fatty acid esters,lanolin, synthetic gums and quaternary ammonium compounds to non-soapsynthetic detergent shampoos to provide the desired conditioningeffects.

The addition of the foregoing expensive finishing agents created newproblems in shampoo formulation due to the relative insolubility and/orchemical incompatibility of the finishing agents. For example, use ofstearic acid as a hair conditioning acid in shampoos either tended tocause instability in liquid shampoos by separation from the liquid phaseor tended to thicken the liquid shampoo 3,590,122 Patented June 29, 1971to a non-pourable paste form. To overcome these new problems, additionalexpensive emulsifying agents and suspending agents were incorporated tominimize problems of physical separation of the finishing agents; or,alternatively, significant quantities of organic coupling agents wereincorporated to solubilize the finishing agents.

Further, the addition of the emulsifying agents, coupling agents, etc.to the shampoo compositions restricted the physical characteristics ofthe final products. Thus, the physical form of the final product couldnot be readily varied from a clear liquid to an opaque lotion withoutcreating a host of new problems.

As an alternative to the foregoing mixtures of synthetic detergents andspecial conditioning agents, blends of synthetic detergents and soapswere evaluated. However, satisfactory soap-detergent conditioningshampoos proved diflicult to formulate and expensive because of the needto use blends of individual fatty acids in order to achieve the desiredbalance of solubility, cleansing, foaming, luster and othercharacteristics needed in the finished shampoo. In view of the foregoingformulation problems, the only shampoos containing a blend of syntheticdetergent and soap which proved commercially successful were those inwhich a stearic or behenic acid salt was present as an opacifying agent.

SUMMARY OF THE INVENTION It has now been discovered that compositionshaving particular utility in the simultaneous cleansing and conditioningof human hair as well as other desirable properties comprise essentiallyin combination a synthetic organic non-soap detergent salt having a longchain containing at least 8 carbons in its molecular structure and aminor proportion of a normally liquid saturated branched-chain higherfatty acid material containing 12- 24 carbon atoms, the ratio ofsynthetic detergent salt to the fatty acid material being from about :1to about 1:1 by weight and effective to yield the desired properties. Apreferred embodiment relates to a pourable aqueous liquid shampooconsisting of about 10 to 40% by weight of said detergent and about 0.5to 5% by weight of isostearic acid having a titer of 10 C. maximumdissolved or solubilized in the aqueous medium having a pH from about 5to 8.5, preferably 7 to 8. The preferred shampoo composition has beenfound to possess exceptional stability, foaming properties andconditioning effects.

These compositions have the dual function of washing and conditioningthe hair, leaving the hair soft and more manageable after shampooing.The need for frequent combing is minimized and the act of combing thehair is accomplished with greater facility due to the elimination oftangled hair. The hair is rendered significantly antistatic and exhibitsgood sheen or luster and curl retention. Other important advantagesinclude a desirable modification of the foaming power so that there isachieved superior foam volume and stability in comparison to similarcompositions wherein stearic acid is substituted for a portion of thebranched-chain acids.

An important property of the liquid shampoos achieved by the combinationof the detergent and the branched chain fatty acid material in theaqueous medium is their stability. The isostearic acid or the like ispartially neutralized to a mixture of the soap and said acid at a pH ofabout 5 to 8.5 and the resulting shampoo has stability at 75 F. and atan elevated temperature of F. without separation, and a capacity toretain opacifying agents in suspension so as to form a stable opaqueliquid shampoo.

Thus, the shampoo compositions of the invention may be formulated in thepopular forms of a clear liquid or a creme lotion without the need forsignificant amounts of additional, expensive ingredients, therebyeliminating the problems common to the incorporation of such additionalingredients. 'For example, the need for additional finishing orconditioning agents, such as synthetic or natural gums and unsaponifiedoils and the instability problems associated with the incorporation ofsuch materials is eliminated. Similarly, the need for the organic,non-aqueous solvent-type coupling agents which have the adverse propertyof causing the hair to become dry and brittle is also minimized.Therefore, the described shampoo compositions provide flexibility in theformulation of liquid products that cleanse the hair and scalp whilesimultaneously imparting luster, beauty and manageability to the hair.

DETAILED DESCRIPTION OF THE INVENTION The suitable liquid branched-chainhigher fatty acids containing about 12 to 24 carbon atoms are known inthe art. In general, they should have a titer of up to about 15 0,usually 3 to 15 C., and preferably about C. maximum. The preferredmaterials productive of optimum results are C to C branched-chain fattyacids, e.g., isostearic acid which is a liquid C saturatedbranched-chain isomeric material of the formula C H COOH havingprimarily methyl branching. For present purposes, it has been found thata suitable commercial material is isostearic acid which is a liquidisomer of stearic acid having a titer of 10 C. maximum and comprisingessentially the 9-methyl and IO-methyl stearic acids. Othercharacteristics of the commercial isostearic acid are a molecular weightof about 284, an iodine value of about 10' maximum and a saponificationvalue of about 180 minimum. Other branched-chain saturated fatty acidsmay be employed including similarly branched-chain lauric, myristic andpalmitic acids which should be prepared in isomeric form so as to haveat titer of up to C. with methyl or ethyl branching preferably at aboutthe middle of the chain. Further examples of suitable branched-chainfatty acids include the 8-10 methyl branched isomers of stearic acid,palmitic acid and the like. Such isomeric branched-chain materials maybe formed in any suitable manner; one method being polymerization of anunsaturated acid which is broken down to yield an unsaturatedmonocarboxylic acid having methyl chain isomers and which is thereafterhydrogenated to a saturated material.

In the manufacture of the shampoo in aqueous form, the branched-chainfatty acid is desirably neutralized at least in part by the addition ofany suitable alkali such as alkali metal hydroxide, or a lower amine,particularly an ethanolamine such as mono-, dior tri-ethanolamine. Theresulting water-soluble soap is formed at a pH of 5 to 8.5, preferably6.5 to 8. The salts of the branched-chain material may be dissolved orsolubilized in the water to the extent that a transparent solution isobtained in the absence of opacifying materials.

The water-soluble organic non-soap detergent may be selected from thegroup consisting of the anionic, nonionic and amphoteric organicnon-soap detergents (including suitable mixtures thereof). Suitabledetergents have a hydrophobic long chain substituent, containing atleast 8 carbon atoms, generally 8 to 26 carbon atoms and preferably 12to 18 carbons in their molecular structure, and at least onewater-solubilizing group selected from the group consisting of sulfate,sulfonate and carboxylate so as to form a water-soluble detergent.

Among the anionic organic compounds that may be used are the long chainsulfated and sulfonated detergents. Suitable examples of these longchain aliphatic detergents are the sulfuric acid esters of polyhydricalcohols incompletely esterified with higher fatty acids, eithersaturated or unsaturated, particularly those whose acyl groups containfrom 12 to 18 carbon atoms, e.g., coconut oil monoglyceride monosulfate,hydrogenated coconut oil monoglyceride monosulfate, tallow monoglyceridemonosulfate; the long chain pure or mixed higher alkyl sulfates of 12-18 carbons, e.g., lauryl sulfate, cetyl sulfate, higher fatty alcoholsulfates derived from hydrogenated or non-hydrogenated coconut oil ortallow fatty acids; the higher fatty acid esters of hydroxy alkylsulfonic acids, e.g., higher fatty acid esters of 2,3 dihydroxy propanesulfonic acid; higher fatty acid amides of amino alkyl sulfonic acids,e.g., the oleic acid amide of amino methyl sulfonic acid, the lauricacid amide of taurine, and the like.

Other appropriate aliphatic long chain sulf(on) ates include fattysulfoacetates, e.g., coconut fatty alcohol sulfoacetates; sulfated fattyacyl monoethanolamides, e.g., sulfated lauroyl monoethanolamide; fattysulfoacetamides, e.g., lauryl sulfoacetamide; lower alkylsulfosuccinates, e.g., dioctyl sulfo-succinate; sulf(on)ated fatty oilssuch as sulf(on)ated castor oil and sulf(on)ated red oil, and loweralkyl esters of alpha-sulfonated higher fatty acids, e.g,, methyl esterof alpha-sulfo myristic acid, sodium salt.

Synthetic detergents having a carboxylate group, and particularly thehigher fatty acid amides of aliphatic long chain amino acid compoundsmay also be included, such as the higher fatty acyl sarcosinates havingabout 10 to 18 carbons, usually 12-24 carbons, in the acyl radical,preferably the water-soluble salts of N-lauroyl or N-cocoyl sarcosine.Other materials are the higher fatty acid amides of polypeptide aminoacids obtained by protein hydrolysis known as the Lamepons and Maypons.Other suitable detergents with carboxylate groups are various amphotericdetergents described hereinafter.

Suitable ether-containing sulfates may be used also such as thealkylphenol polyglycol ether sulfates, e.g., lauryl phenolpolyethyleneoxy sulfates, and alkyl polyglycol ether sulfates, e.g.,lauryl ethyleneoxy sulfates, each containing about 10 to 18 carbons insaid alkyl groups and about 2 to 10 moles of ethylene oxide, usually 3-4moles, per molecule.

The alkyl aryl sulfonates may also be used as the anionic detergentalthough they are not usually preferred in shampoos because of theirexcessive drying power. Typi cal of this class of compounds are thehigher alkyl aromatic sulfonates where the nucleus may be derived frombenzene, toluene, xylene, phenol, cresols, naphthalene, etc. The alkylsubstituents may be branched or straight chain, such as decyl, dodecyl,keryl, hexadecyl, mixed long-chain alkyls derived from long-chain fattymaterials, cracked paraflin wax olefins, polymers of lower monoolefins,etc. Examples of the classes are the higher alkyl benzene sulfonateswherein the alkyl group contains 8 to 18 carbon atoms, and preferablyabout 12 to 15 These various anionic detergents are used in the form oftheir water soluble or water dispersible salts such as the amine, alkalimetal and alkaline earth metal salts. Examples are the sodium,potassium, magnesium salts, ammonium, monoestanolamine, diethanolamine,triethanolamine, triethanolamine salts, and mixtures thereof.

Further suitable organic detergents include non-ionic detergents such asthe lower alkylene oxide condensation products of hydrophobic compounds,e.g., ethylene oxide condensates with higher fatty acids, higher fattyacid amides, higher fatty alcohols or alkyl aryl hydrocarbons, having atleast 5 and usually from about 5 to 30 ethyleneoxy groups per molecular.The corresponding higher alkyl mercaptans of thioalcohols, orpolyoxypropylene glycols of at least 900 molecular weight condensed witha sufficient number of ethylene oxide groups as known in the art may beused also. Other non-ionics are the alkylolamine condensates of higherfatty acids such as lauric and myristic diethanolamide, coconut fattyacid diethanolamide, and the like.

Other suitable surface-active agents which may be used include thehigher alkyl amine oxides such as lauryl dimethyl amine oxide. In placeof the lauryl radical, other long chain alkyl radicals, preferablyhaving 1 0 to 18 carbon atoms, may be used also. In place of either orboth methyl radicals, there may the other lower alkyl or hydroxyalkylradicals such as having two carbon atoms each. Suitable examples includea mixture of higher alkyl di methy lamine oxides having essentiallyabout 12-14 carbons in the higher alkyl groups.

Any of the usual amphoteric (ampholytic) detersive materials may beemployed in the compositions of the present invention. Among those arefatty or higher alkyl imidazolines, such as 2-coco-1-hydroxyethyl-1carboxymethyl imidazoline known as Miranol CM; and the higher alkylbeta-alanines such as dodecyl beta-alanine known as Deriphats, saidmaterials having usually an alkyl group of 10 to 18 carbons and thecarboxylate group being in the form of the water-soluble salt. Furtherexamples are the disodium salt of 2-lauryl-cycloimidium-l-ethoxyethionicacid-l-ethionic acid and its corresponding l-lauryl sulfate derivative.

The mixture of detergent material and branched-chained acid materialshould be suitably proportioned to achieve the desired results such ashair conditioning in the use of the shampoo, improved foam consistencyor solubilization, etc. In general, the ratio of detergent material tosaid fatty acid will be within the range of about 80:1 to about 1:1 byWeight, usually 30:1 to 3:1, and sufficient to obtain the desiredbeneficial effect therefrom. It has been determined that optimum effectsare obtained when the fatty acid material is present as a minorproportion of the order of 0.1 to 10%, usually at least about 0.5% andup to 5%, by Weight of the final composition, which is dissolved ordispersed in water. In the final composition, the synthetic detergentsdesirably comprise at least about %-40%, by Weight, preferably to byweight, with water as primarily the balance in the liquid shampoos.

It is preferred to use said isostearic acid or the like in combinationwith an alkylolamide of a higher fatty acid, such as thediethanolamides, monoethanolamides, and iso propanolamides of higherfatty acids having 8 to 18, preferably 10 to 14 carbons. The higherfatty acid alkylolamide is present in a minor amount, such as from about1 to 10% by weight of the composition. Such combination is selected fromthe range of about 10:1 to 1:10 by weight of fatty acid material tofatty acid alkylolamide so as to produce improved overall latheringproperties. The products containing the blend exhibit a quick, copiousand yet stable foam.

The resulting liquid shampoo having the solubilized branched fatty acidmaterial has a desirable capacity for retaining opacifying agents insuspension even when the shampoo is highly fluid. Any suitableopacifying agents may be used to produce an opaque lotion-like productincluding excess detergent, lanolin, and preferably higher fatty acidesters such as ethylene glycol distearate and monostearate in sufficientamount to opacify the product and be retained in a stable suspensionupon aging. The opacifying agents such as the ester are generallyemployed in a suitable amount from about 0.5 to 10%, preferably 1 to 5%by weight of the shampoo.

In general, the products are manufactured in the usual manner with thedetergent, fatty acid and alkali being mixed in water at an elevatedtemperature to form a stable, homogeneous mixture. It is preparedpreferably in a readily pourable form such as having a viscosity ofabout 10 to 400 seconds, preferably about to 110 seconds, as determinedon a No. 5 Raymond flowmeter. The specific gravity of the liquidshampoos is desirably at least about 1.02 and preferably within therange of 1.025 1.03.

It is common to add various adjuvant materials to shampoo compositionsand the like. Thus, the shampoo ordinarily will contain a compatibleperfume and color. Other ingredients may include a small amount of abuffer material to aid in the adjustment and maintenance of the desiredpH of the finished product. Suitable buffering materials include borax,the various inorganic water-soluble phosphates such as disodiumphosphate, or sodium pyrophosphate, citric acid, etc. Sequesteringagents such as the water-soluble salts of ethylene diamine tetra-aceticacid maybe employed also. Other ingredients which may be used inshampoos for imparting desired qualities and may be incorporated in thepresent compositions include superfatting materials such as lanolin,liquid lanolin or ethoxylated lanolin, fatty alcohols, fatty acids,fatty acid esters, etc., generally in minor proportions, e.g., up toabout 5% by weight. The higher fatty alcohols include myristyl, cetyland stearyl alcohols, etc. Glycerine, ethanol or propylene glycol may beadded in small amounts generally. Similarly, antiseptics or otheranti-bacterial agents may be used if desired. Preservatives such assodium benzoate and the like may be added to prevent mold growth. Gummucilages such as carboxymethylcellulose, and the like may be used ifdesired. Preservatives such as sodium benzoate and the like may be addedto prevent mold growth. Gum mucilages such as carboxymethylcellulose,and the like may be used as desired similarly.

The following specific examples are further illustrative of the natureof the present invention, and it is to be understood that the inventionis not limited thereto. All parts are by Weight unless otherwiseindicated.

EXAMPLE I Ingredients: Percent Sodium lauryl sulfate 17.6Triethanolammonium lauryl sulfate 1.9 Isostearic acid 2.0 Ethyleneglycol distearate 2.0 Lanolin 0.5 Potassium hydroxide (34.2% solution)1.0 Lauric-myristic (70:30) diethanolamide 1.5 Water Balance The abovecomponents except for the amide are combined with heat sufficient tomaintain a fluid state at about 160 F. for about 10 minutes and to forma uniform mixture. The sodium lauryl sulfate is listed on an activeingredient basis and is added as a 28% aqueous paste containing inaddition about 2% unsulfated fatty alcohol and 0.2% sodium chloride. Thetriethanolamine lauryl sulfate is added as a 41% aqueous solution withabout 1.5% unsulfated alcohol and 1.5% triethanolamine chloride asimpurities also. The isostearic acid is a liquid material and comprisesessentially 9- and IO-methyl stearic acid having a titer of 10 C.maximum. The resulting mixture is cooled with the amide being added at130 F., and a very small amount of color and preservatives at about F.The pH is adjusted with the addition of citric acid to 7.5. The productis a stable, readily pourable opaque lotion shampoo having a specificgravity of 1.03 and a viscosity of about 50 seconds using the No. 5Raymond flowmeter.

This lotion shampoo provides excellent foam quality andhair-conditioning effects superior to a similar product containingstearic acid in place of a portion of the isostearic acid.

EXAMPLE II Ingredients: Percent Sodium lauryl sulfate 17.6Triethanolammonium lauryl sulfate 1.9 Isostearic acid 3.3 Potassiumhydroxide (34.2%) 1.1 Lauric-myristic diethanolamide 1.5 Water BalanceThe above shampoo is prepared as in Example I and is a clear, stable,pourable liquid at room temperature having satisfactory foaming,cleansing and hair-conditioning properties.

EXAMPLES III-V Ingredients: Percent Sodium lauryl sulfate 17.6Triethanolammonium lauryl sulfate 1.9 Isostearic acid 1.5 Potassiumhydrdoxide (34.2%) 1.1 Lauric-myristic diethanolamide 1.5 Ethyleneglycol distearate 1.4 Water Balance The above shampoo formulations areprepared as in Example I with 1%, 2% and 4% distearate respectively. The2% and 4% formulas were opaque and the 1% formula was slightly lessopaque. All formulas had a satisfactory pH of about 8 and viscosities ofabout 30 seconds using the No. 5 Raymond flowmeter with desirablestability and effective cleansing and hair-conditioning properties.

EXAMPLE VI A similar formulation is prepared as in Example III with a 1%content of isostearic acid, 0.5% double-pressed stearic acid and 3%ethylene glycol distearate. The resulting product is an effective,stable, pourable lotion shampoo whereas a similar product containing1.5% stearic acid and free of isostearic acid is found to exhibitunsatisfactory stability.

EXAMPLE VII Ingredients: Percent Sodium cocoyl N-methyl taurate 19Isostearic acid 2 Ethylene glycol distearate 2 Potassium hydroxide(34.2%) 1 Lauric-myristic diethanolamide 1.5 Water Balance The aboveshampoo is prepared as in Example I and is a relatively thick, butpourable, effective foaming shampoo product also.

EXAMPLE VIII Alkyl mixture derived from coconut oil comprising about 8%Ca, 7% C10, 48% C12, 18% C14, 9% C10 and 2% C18.

The above formulation is prepared as in Example I and is an effectivefoaming shampoo product having a viscosity of 10 seconds using the No. 5Raymond fiometer.

EXAMPLE IX Ingredients: Percent Triethanolammonium linear dodecylbenzene sulfonate 19 Isostearic acid 2 Ethylene glycol distearate 2Potassium hydroxide 34.2%) 1 Lauric-myristic diethanolamide 1.5

Water Balance The above ingredients are prepared into a satisfactorylotion shampoo product having a second viscosity using the Raymondflowmeter.

Although the present invention has been described with reference toparticular embodiments and examples it will be apparent to those skilledin the art that variations and modifications of this invention can bemade and that equivalents can be substituted therefor without departingfrom the principles and true spirit of the invention.

Having thus described the invention, What is claimed 1. A pourable,liquid shampoo consisting essentially of 15% to 30% by weight of analkyl sulfate salt containing 12 to 18 carbon atoms in the alkyl groupand selected from the group consisting of sodium and triethanolaminesalts and mixtures thereof, 0.5% to 5% by weight of liquid isostearicacid having a titer of 10 C. maximum and containing a methyl group inthe 8, 9 or 10 position, 1% to 5% by weight of ethylene glycoldistearate, 1% to 10% by weight of a higher fatty acid alkylolamideselected from the group consisting of monoethanolamides,diethanolamides, and isopropanolamides of fatty acids containing 8 to 18carbon atoms, and water, said shampoo being in the form of a stable,opaque lotion having a pH of 6.5 to 8.

References Cited UNITED STATES PATENTS 2,812,342 11/1957 Peters 2604092,756,178 7/1956 Verblen 16787 3,267,039 8/1966 Schneider 252153 OTHERREFERENCES Sagarin et al., Cosmetics Science and Technology, Sept. 16,1957, pp. 387, 388, 390, 393, 398, 399, 403, 404.

Wells et al., Cosmetics and the Skin, 1954, pp. 397-413.

Rees, American Perfumer and Cosmetic, vol. 81, No. 4, pp. 37-42, April1966.

Bennett, The Chemical Formulary, 1965, vol. XII, pp. 201202.

The Condensed Chemical Dictionary, 7th edition, 1966, p. 527.

ALBERT T. MEYERS, Primary Examiner A. J. ROBINSON, Assistant ExaminerU.S. Cl. X.R. 2521l7, 121

